Large databases often include data of many different types, and may include personal data. Unauthorized access to personal data may constitute a breach of privacy or a security risk. Some types of personal data may be more sensitive than others in that unauthorized access represents a more significant privacy breach or security risk.
Accordingly, maintainers of databases may divide database contents to segregate sensitive data into multiple subsets, conventionally, all subsets are provided with a common key field, allowing the subsets to be joined. However, such security measures are imperfect, as the subsets may be easily reconstructed. Additional protection may therefore be provided for sensitive data. For database contents may be encrypted. Unfortunately, such protection may be costly and/or inefficient. For example, encryption imposes significant computational overhead, and may impede efficient database operations, including search and retrieval operations.
Accordingly, new methods, software and devices for storing relational data are desired.